i think you've misread. Hera is not Hargaan's mother. It was another woman, who loved Zeus to the point she's 'blinded by love'. But because of her sincere love for him, Zeus also fell for her, and favored hargaan because of it (which hargaan never knew).
As for Hera, she despises Zeus. In the beginning they joined hands to get what they wanted, which was Zeus wanting a perfect killing machine offspring (like Hercules) and Hera wanting power and being queen of Olympus. But because Hera was never able to produce an heir that Zeus desired, he essentially played a role in sabotaging her ambitions, hence Hera hating Zeus, while Zeus remains indifferent to her.
And Hera dies by Hercule's hands-who after knowing the truth behind his mother's death, went in a frenzy of killing anyone who contributed in the death of his mother.
Ok so can any explain the deal between Zeus and Hera? Did he love her? I mean it said that Hera did love him unconditionally so did that make Zeus have some kind of affection towards her and their child, haargan too? And what even happened to her?